Afraid to go to the doctor because I'm fat.

I'm 17 years old and I have a doctors appointment tomorrow for the last time seeing my pediatrician and in February I have an obgyn appointment because a year ago I became sexually active. I hate going to the doctors and I have pushed back for so long. I hate going into the doctors office and getting on the scale and the nurse has this weird look on their face like "Damn,she is fat as f*ck." I can't stand the doctors for that reason like I haven't stepped on a scale in over a year ago I'm damn there 300 pounds (don't judge) probably over 300 pounds I wouldn't know. I'm sorry for posting this anonymous but it's embarrassing. I'm ashamed I feel this way I'm ashamed that I'm so fat.